Like All Rolex watches, the Oyster Perpetual Datejust 31 is covered with the Superlative Chronometer certification redefined by Rolex in 2015. This designation testifies that each watch leaving the brand’s workshops has productively been through a series of tests carried out by Rolex in its individual laboratories As outlined by https://www.watchesworld.com/11-of-the-best-womens-watches/